One can create a "block" just for scrolling text or even images within your forums.. Setting the block up as if it's a category then create an blank area within the text field to create the scrolling text or images..

Using the "scroll" code as posted below:

Code:

[scroll]Your text here[/scroll]

Your text here

Or Images

Or even animated gifs but this I'll force it updown

To locate this option.. Click the "more" button within your tool tray at the top of this text area.